The overall objective of our research program is to identify the biopsychosocial origins of the Type A behavior pattern. During the next three years, we propose to assess the familial patterns of individual Type A behaviors, their associated cardiovascular reactivity, and their determinants including family history of CHD, sex, modes of coping with and experiencing anxiety and anger, and parental childrearing practices and attitudes. To achieve this objective, all children currently enrolled in the ongoing longitudinal cohort study begun in 1979, their siblings attending school in the same school district as the case children, and their parents (number of families = 187) will be asked to participate in an individually administered experimental session, during which they will perform a difficult cognitive task, a frustrating psychomotor task, and an isometric exercise while their blood pressure and heart rate are intermittently measured. Participants will be administered the Type A interview and several questionnaires on their modes of coping with anxiety and anger. Parents only will complete several questionnaires on their reactions to their children's achievement and attitudes toward childrearing. Family medical history and Framingham Type A scores were already obtained from the parents and MYTH Type A ratings of the children were already obtained from the children's classroom teachers. In addition, three substudies of children only are planned. The aims of these substudies are to assess (a) the generalizability of children's cardiovascular responses to laboratory stressors to those induced by a naturally occurring stressor -- making a speech in class; (b) the consistency across one year of children's task-induced cardiovascular responses and their Type A interview behavior; and (c) the consistency of children's Type A behaviors in the classroom and their determinants across the six years during which approximately 190 children have been enrolled in the longitudinal study of children's Type A behaviors.